AERMOD View
Posts category: aermod-view
15
Jun 2018
AERMOD View - Modeling NO2 in AERMOD – ARM2
One of the biggest changes to the AERMOD modeling system in the 18081 model update was the removal of the original Ambient Ratio Method (ARM) for analyzing conversion of NOx to NO2. This option, based on Chu & Meyer’s 1991 work presented at that year’s Air & Waste Management Association’s annual conference, used a single ratio to convert all NOx concentrations to NO2. The national default value was 75% for annual averages, and subsequent guidance recommended a value of 80% for the hourly standard.
15
Feb 2018
AERMOD View - Choosing Pollutants
As the preferred air dispersion model for analysis of air pollutant concentrations in the ambient environment up to 50-km, AERMOD is used for a wide variety of buoyant and neutrally-buoyant releases. One recurring question about AERMOD is what pollutants it can (or cannot) model. Coded into the model is a list of pollutant types used to identify the pollutant being modeled for a particular run.
15
Jan 2018
AERMOD View - When Numerical Values Are Outside AERMOD’s Default Threshold
A standard model run using the AERMOD air dispersion model produces numerical output with up to 13 significant figures (e.g., xxxxxxxx.xxxxx). Projects which use very low or very high emission rates may run into a problem where the model outputs values which do not fit properly within this limit. For examples, concentration values of 1E9 units or higher will result in a field of asterisks written to the output file as shown below.
